1. Field of the Invention
The present invention relates to a planar transformer, and more particularly, to a planar transformer having a dual-bobbin structure.
2. Description of the Related Art
Recently, power supply units have been required to be slimmer due to the trend towards slimmer electronic devices.
Even if power supply units can have slim profiles by driving power terminals at high frequencies, the slimming of power supply units is limited by magnetic devices and capacitors contained therein.
Slimmer capacitors with heights and diameters small enough for slim power supply units have been recently developed, whereas there has been not much progress in the slimming of magnetic devices.
As for inductors and transformers, which are representative components of magnetic devices, a multilayer board having a printed circuit is stacked to thereby implement a winding of a magnetic device. In this way, magnetic devices can be slimmed; however, this process increases the manufacturing cost of the multilayer board.
Furthermore, the greater the number of turns (winding), the thicker the multilayer board becomes, adversely affecting the slimming of devices.